The Cape Cod Canal literally is looked down upon. Thousands of drivers can’t seem to get over it fast enough.

But they’re missing an engineering and recreational marvel, say fans preparing to celebrate the canal’s 100th birthday on July 29.

“We’re celebrating that it’s one of the most magnificent attractions,” said Marie Oliva, co-chair of the Cape Cod Canal Centennial Celebration Committee. “It’s the widest sea-level canal without locks in the world, and it’s had a tremendous impact. The canal was made as a shortcut, but they also put in these recreational banks that make it a place for everyone.”

After three years of planning, a five-day celebration in Bourne and Sandwich kicks off July 25 with tours of historic ships and culminates July 29 with a free festival and fireworks. The centennial already is bringing more appreciation to the canal.

“More people are aware that the canal is not just a barrier and that there is something good going on underneath the bridges,” said Samantha Gray, ranger at the Canal Visitor Center. “People say, ‘We decided to stop because we know you’re having a birthday.’”

Gray welcomes about 40,000 people a year to the center, which has exhibits and runs daily tours, hikes and educational programs for kids and adults. It’s a good starting place for an orientation to the canal’s two 7-mile paved trails, nine recreation and picnic areas, marina, two campgrounds and Scusset Beach State Reservation. About 3 million people a year walk, bike, in-line skate, fish and camp at the canal.

“The canal is a beautiful blend of a natural and engineered environment,” Gray said. “You get a snapshot of so much just by being on its banks.”

Consider what a canal-less Cape was like in the 19th century. Ships wrecked every week or two as they navigated the strong currents and dangerous shoals around the Cape, impeding trade and risking lives.

“It was absolutely a big deal when it opened,” Gray said. “It had been discussed for so long, since the 1600s, so that when it finally became a reality people celebrated.”

You can see the excitement and hopefulness in the visitor center’s poster-size 1914 photographs of the July 29 opening. What isn’t apparent is how the dream shortly proved unrealized. Boats ran aground in its too narrow and shallow waters and struggled in the strong currents as they waited for the low bridges to open.

“It was just too challenging for a lot of mariners, and there were a few accidents that gave it a bad reputation,” Gray said.

Page 2 of 2 - It would have remained a failure, if the U.S. government hadn’t purchased it for $11.5 million in 1928 and then worked seven years to remove 30 million cubic yards of earth to create a depth of 32 feet and width of 540 feet. Operated by the Army Corps of Engineers, the 17.5-mile canal now is traveled by about 20,000 commercial and recreational boats a year. In 1985, it was recognized as a National Historic Civil Engineering Landmark.

Visitors can travel the canal on Hyline Cruises, which runs sightseeing and music cruises departing from Onset Harbor. Kids ages 5 to 12 ride free with a parent on the two-hour 4 p.m. cruises Monday through Saturday. Or they can take a virtual boat ride at the visitor center, where they also can watch live radar of passing ships and see the centennial exhibit.

At the start of the centennial celebration, two rare ships will dock at the Massachusetts Maritime Academy in Bourne. On July 25-27, people can tour the 295-foot U.S. Coast Guard Cutter Eagle, the only active commissioned steel-hulled sailing vessel in U.S. military service. On July 26-27, people can tour the 1841 whaling ship the Charles W. Morgan, the country’s oldest commercial ship still afloat.

A free music festival featuring 100 years of popular music runs noon to 4 p.m. at the Briggs-McDermott House, 22 Sandwich Road, Bourne, and a parade of lighted boats travels the canal at 9 p.m. July 26. At Scusset Beach Reservation, a Family Fun Day features music, arts and crafts, marine and animal programs from 2 to 5 p.m. July 27, run by Friends of Scusset Beach.

The celebration culminates with the 100th anniversary commemoration and “Canaliversary” from 1 to 9:30 p.m. July 29 in Buzzards Bay Park. A commemoration will honor the people who built the canal and features the Canal Festival Youth Orchestra. The free festival, which starts at 4 p.m., will have a tugboat parade, bands, maritime-themed games, engineering activities and antique cars. About 9 p.m., barges in Buzzards Bay will set off fireworks expected to be visible throughout the bay area.

Those driving over the Sagamore or Bourne bridges when the sky lights up might want to detour and find a place to watch.

For information on events and parking, go to www.capecodcanalcentennial.com.

Jody Feinberg may be reached at jfeinberg@ledger.com or follow on Twitter @JodyF_Ledger.